Barbecue grill have become so popular for outdoor home cooking, as well as for commercial use, that they are now a significant source of air pollution in the form of smoke. Increasingly tighter environmental controls demand cleaner burning systems. One way to eliminate smoke is to equip the grill with a flue having an afterburner or incinerator to heat and burn the solid smoke particles which form visible pollution. The particles are converted to invisible gaseous compounds, and are carried up the flue by convection.
An example of an afterburner type smoke incinerator in the prior art is seen in Kalenian, U.S. Pat. No. 5,505,190. A structure is shown which admits smoke from the grill lower housing, bums the smoke in a gas flame, and conveys the gases up a stack.
While the above-described grill smoke incinerator is functional for reducing smoke, it displays shortcomings inherent in it's design. Hot gases and smoke particles tend to rise into the upper housing or lid of the grill, yet the above device takes gases from the lower housing, resulting in a weak convection flow. The incinerator flame is directed into a straight pipe, a geometry not suited for the venturi effect. The incinerator works only while the housing lid is closed, and smoke accumulates within the housing. With the housing lid open, while attending to cooking, hot gases and smoke will escape directly upward.
Accordingly, there is a need to provide a barbecue grill having a smoke incinerator mounted in the housing lid, where full use can be made of the upward convection flow of the hot gases and smoke particles, to fully scavenge all smoke from the housing.
There is another need to provide a barbecue grill of the type described, and having an incinerator burner geometry which will produce a venturi effect, to more aggressively draw the smoke particles from the housing.
There is yet another need to provide a barbecue grill of the type described, and having a means to prevent unignited gas from accumulating in the housing, for safety.